Control device



Oct. l, 1940. R, W, GOFF 2,216,588

CONTROL DEVICE Filed May 19, 1958 Inventor:

His A horney.

Robert W. Goff; 48

Patented Oct.- 1, 1940 UNITED STATES CONTROL DEVICE Robert W. Goff,Schenectady, Y., assignor to I General .Electric Company, a corporationof New York Application May 19, 1938, Serial Nm 208,864

Claims.

My invention relates to control devices, more particularly to a circuitcontrolling device for governing machine-tool feed motors vand the like,and has for its object the provision of a device of this character whichgives a predetermined timing interval in performing its control functionand which provides means for accurately adjusting this timing interval.

For feeding cutting tools into the work during machining operations inconnection with automatic machinery, such as planers, shapers andmilling machines, it is necessary to provide'a control which will permitof easy adjustment and extremely accurate performance. In'these machinesat the end of each cutting stroke, it is desirable to feed the tools apredetermined amount preparatory to taking the next cutting stroke. Toachieve the smooth, accuratelymachined surfaces generally desirable,each feeding of the tool during a particular operation should beprecisely a predetermined amount as the cutting proceeds across theWork. Accordingly, I have provided a device embodying my invention inone form for the purpose of starting and stopping the tool feed motorson a planer, although it is obvious that a control device of thischaracter may be used with feed motors on a wide variety of machinery,as well as, having broad application to fields in which time intervalcontrol is necessary.

In the instant use described hereinafter, I prefer to operate thecontrol device directly off the large bed-driving motor for the planerthrough an electro-magnetic clutch. When the planer bed arrives at itslimit of movement and operates its limit switch, the clutch is energizedand thereby engaged and at the same time the tool feed motor of theplaner is energized and operates to advance the tool during the returnstroke of the planer for the next cut. In the meantime, the controldevice is operated by the main driving motor, and after a predeterminedperiod of operation for which the device is adjusted, it opens thecircuit of the feed motor, the tool having then been advanced thedesired amount for the next cut. Simultaneously with the opening oi.'the circuit of the tool feed motor, the electromagnetic clutch of thecontroller is deenergized and an energy storing spring causes the timingmechanism of the control to be returned to its original position readyfor a repeat performance.

For a more complete understanding of my invention, reference should nowbe had to the accompanying drawing in which Fig. 1 is an elevationalview of a casing containing a controller embodying my invention showingthe cover plate -of the gear box partly in section to illustrate detailsthereunder; Fig..2 is a sectional view of the side of Fig. 1 revealingthe-controller mechanism; Fig. 3 is a front elevational view of Fig. 1partly in section'to reveal details of the gearing mechanism; Fig. 4is'a plan view of the controller in section taken alongA the line 4-4ofFig. 2; Fig. 5isA a' perspective view ofthe controller mechanism;-'andFig. 6 is 'an enlarged perspective view of the switching element of myinvention.

Referring to the drawing-I have shownmy invention in one formas appliedin the circuit of a tool feed'motor used on-a planer. The mechanism isshown' enclosedv in a suitable casing I0, preferably of iron-magneticmaterial provided with ai front wall VIl secured bythe bolts I2 and apair of si'de -walls I3 fastened by screws I4 threaded into the casingI0. Journaled through a thickened portion in the rear wall of the casingI0 is a drive shaft I5 which may be geared directly to the driving motorofthe planer (not shown). Arranged to operatively connect the shaft I5to an elongated driving gear I6 is an electromagnetic clutch I1 whichmay be energized through a suitable A. C. or VD. C. circuit I'Ia whenthe-planer bed has reached the end of its cutting stroke. Continuouslymeshed with the driving gear I6 are' a pair of traveling pinions I8 andI9, set at each side of the driving gear I6, being mounted fortranslational movement in opposite directions along 'threaded screws 20and 2l when rotated in the same direction with respect to each vother bythe driving gear. The threaded members and 2i are supported at one endby a bracket 22 attached to the top wall 23 of the casing Il). Forpurposes of adjustment, to be explained hereinafter, the threadedmembers 20 and 2| project through the front wall I I of the casing I0and terminate with the slotted heads 24 and 25 which are accessible fromthe outside of the casing I0, when the cover plate 25 of the gear box 21at the front of the casing is removed. Pinned to the screw members 20and 2| are a pair of operating pinions 28 and 29-`having the clutchfaces 3U and 3| extending circumferentially around the screw members 20and 2l and projecting in the direction of the traveling pinions I8 andI9. On the vtraveling pinions I8 and I9, I have provided the clutchfaces 32 and 33 which are arranged to engage the corresponding clutchfaces and 3| for operating the operating pinions 28 and 29 when eitheroi' the pinions I8 or I9 has traveled on the threaded members 20 and 2Iadjacent the operating pinions 28 and 29.

By threading the screw members 28 and 2I in opposite directions, thatis, giving them left and right hand threads respectively, rotation ofthe driving gear I8 in either direction will cause one of the travelingpinions I8 and I8 to move in the direction of one of the operatingpinions 28 or 28 while the other of the traveling pinions moves awayfrom the corresponding operating pinion. By the device of an idlingpinion 34 between the operating pinion 28 and a suitable control member,such as a 'large switching gear 35, and by meshing the operating pinion28 directly with the control member or switching gear 35, the operationof the gearing system is such that by rotating the driving shaft I ineither direction, the switching gear 35 is caused to revolve in only onedirection. In this way the controller is provided with a reversiblefeature since the driving shaft I5 may be operated in either direction,yet the switching gear 35 will operate only in the desired direction.

Journaled in the rear wall of the casing and projecting through thefront wall II is a switching shaft 38, upon which the switching gear 35is loosely mounted. Projecting from one face of the switching gear 35are a pair of pins 31 and 38 which cooperate with a suitable switchingmember 38 secured on the shaft 38 for disconnecting a movable contact 48from a fixed contact 4I carried by the switching member 38. Since theswitching gear 35 will only turn in one direction upon rotation ineither direction of the driving gear, it will always turn in a clockwisedirection. as viewed from the right end of the shaft 38, for disengagingthe 'contacts 48 and 4I when it is operated. Although I have shown thecontrol member 35 as a switching gear provided with the pins 31 and 38for operating an.elec trical switch, I do not wish necessarily to belim.- ited in this respect, since it is believed obvious that thecontrol member 35 might well be a rheostat arm. an operating member fora nonelectrical device, such as a clutch, or the like without departingfrom the spirit and scope of my invention.

Connecting the contactsy 48 and 4I of the switching member 38 in circuitwith the feed motor to be controlled and in an auxiliary circuit throughwhich the electromagnetic clutch I1 is energized are a pair of leads 42and 43. I prefer to form the switching member 38 of suitable insulatingmaterial having an insulating disk 44 spaced from an insulating plate 45by an insulating sleeve 48 which fits over the shaft 38 and provides aspool about which the leads 42 and 43 may wind when the shaft 38 isrotated. The operating pins 31 and 38 projecting from the switching gear35 may also be suitably insulated or be formed of insulating material.As shown in Fig. 6, the fixed contact 4I is supported by an angularterminal member 4Ia secured to the plate 45. The movable contact 48 issupported by a flexible terminal strip 48a having its fixed end securedto a spacer block 4Ib of insulating material fastened near the bottom ofthe plate 45, the spacer block 4Ib serving to separate and also supportthe terminal strips 48a and 4I a.

At the front of the casing I8 in the gear box 21 which ls closed by thecover plate 28 is an adjusting gear 41 keyed to the shaft 38 andslidable thereon. Normally the adjusting gear 41 is in engagement with astop 48 attached to the casing I8 by means of screws 48, which preventsthe shaft 38 from rotating. By pulling ananas the adjusting gear 41forward out of contact with the teeth of the stop 48, it is possible torotate the gear 41 the desired amount for setting the controller.Rotation of the" gear 41 turns the shaft 38, and with the shaft theswitch member 38 and through the pins 31 and 38 the switching gear 85 isdriven. The switching gear 35 drives the operating pinions 28 and 28 andthrough them adjusts the positions of the traveling gears I8 and I8. Ofcourse, the distance these traveling gears I8 and I8 have to travel toactuate the switching 'gear to open the feed motor circuit determinesthe timing setting of the controller, and the period during which thetool feed motor operates is thereby regulated. Carried by the coverplate 28 is a stop 58 which limits the amount that the adjusting gear 41may be turned by bumping a projection 5I extending from the gear. At anytime when the controller is set to perform its timing function. thetraveling pinions I8 and I8 are spaced equidistant from the operatingpinions 28 and 28, so that in either direction of rotation of the shaftI5, one of the traveling pinions must move a predetermined amount beforethe switching operation is effected. 1

Loosely journaled on the shaft 38, continuously meshed with the drivinggear I8 is a return gear 52 arranged to return the traveling pinions I8and I 8 to their starting' position after the switching has occurred andthe electromagnetic clutch I1 de-energized. By means of a double-actingspring 53 encircling the shaft 38 and attachedat each end to the members54 and 55 which cooperate with a detent member 58 positionedtherebetween and a projection 51 from the gear 52 also extending betweenthe members 54 and 55, energy is stored in the spring 53, when thecontroller operates, which is used to return -the controller to itsstarting position when the clutch I1 is disconnected. The return gear 52together with the spring force of the spring 53 also serves to hold thedriving gear I8 stationary to force the traveling pinlons I8 and I8 tobe threaded to the new position, while an adjustment is made by theadjusting gear 41.

In operation of the controller, the drive shaft I5 is directly geared tothe reversing driving motor of the planer to be controlled. When theplaner reaches the end of its cutting stroke, a limit switch is thrownwhich reverses this motor. Simultaneously, the electromagnetic clutch I1is caused to be energized and the feed motor which feeds the tool isplaced in operation. The rotational force of the shaft I5 is thentransferred to the driving gear I8, and We will assume for purposes ofdiscussion the direction of rotation to be such that the travelingpinion I8 is threaded toward the operating pinion 28 while the othertraveling pinion I8 is threaded a corresponding amount away from theoperating pinion 28. When the cam face 32 of the traveling pinion I8engages the cam face 38 of the operating pinion 28, the idling gear 34and through it the switching gear 35 is rotated in a clockwisedirection. 1

Rotation of the switching gear 35 forces the pin 38 against the movablecontact 48 and digengages this contact from the stationary contact 4I onthe switching member 38. When the controller circuit is broken, ashereinbefore explained. the feed motor circuit is deenergized, thefeeding now being complete: and simultaneously, the electromagneticclutch is deenergized to free the shaft I5 from the driving gear Il.Immediately upon disengaging the shaft I5 from the gear I6, the springforce which was built up in the energy storing spring 53 causes thereturn gear 52 to rotate the gear I 8 which threads the travelingpinions I8 and I9 back to their starting position and permits thecontacts 40 and 4I to reengage. In this manner the feeding of the tooloccurs during .the return stroke of the planer, and thereafter the toolis in its correct cutting position ready for the cutting stroke.

Referring now to Fig. 2 and Fig. -3, to assemble the traveling pinionsI8 and I9 and the operating pinions 28 and 29 on their respectivethreaded members 20 and 2| and to adjust the clutch faces 30, 32, 3|,and 33 so they are in respective engagement at a zero setting of theadjusting gear 41, the threaded members 20 and 2I are rst pushed throughthe front wall II of the casing I0. The operating pinions 28 and 29 areslipped over the threaded members 20 and 2| and meshed with theswitching gear 35. By screwing the threaded members 20 and 2I at theirslotted head portions 24 and 25 with a screw driver, the travelingpinions I8 and I9 may be meshed with the driving gear I 8 and slidablydrawn up close to the operating pinions 28 and 25 which are looselymounted on -unthreaded portions of the members 20 and ZI. The ends ofthe members 20 and 2l extending into the casing I may then be projectedfor support into holes in the supporting member 22. Each of thetraveling pinions I8 and I9 may then be drawn up to engage its clutchface with the mating clutch face on the operating pinions 28 and 29,leaving suillcient clearance between the clutches for easy engagementand disengagement. ions 28 and 29 is a tapped hole 5B into which atemporary set screw may be turned for holding the operating pinions 28and 29 in place on the members 20 and 2l, While holes for thepins 59 and60 are being drilled and the pins inserted. After pinning the operatingpinions 28 and 29 to the members 20 and 2|, the switch member 39 may bepinned to the shaft 36 so that the movable contact 40 is disposedadjacent the switching pin 38 on the switching gear 35 ready to bedisengaged by the rotation of the gear 35. The controller is then readyto be adjusted by rotation of the adjusting gear 41 which causes thetraveling pinions I8 and I9 to be threaded back away from the operatingpinions 28 and 29 equal distances, as hereinbefore explained, that inturn determine the timing of the control device for either direction inwhich the driving shaft I may be rotated.

While I have shown a particular embodiment of my invention, it will beunderstood, of course, that I do not wish to be limited thereto sincemany modifications may be madeand I therefore contemplate by theappended claims to cover any such modifications as fall within the truespirit and scope oi' my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A circuit controller provided with switching means adapted to beoperated after a predetermined time interval comprising driving meansi'or said controller mounted for rotation in either direction, timingmeans driven by said driving means including a pair of traveling membermounted for travel in opposite directions for providing saidpredetermined time interval of Provided in each oi.' the operatingpinoperation in either direction of rotation of said driving means, andmeans including a member associated with said timing means operable in apredetermined direction yby said traveling members selectively foractuating said switching means.

2. A circuit controller provided with switching means adapted to beoperated after a predetermined'time interval comprising driving meansfor said controller mounted for rotation in either direction,` timingmeans including a pairoi' traveling pinions driven by said driving meansand mounted for travel in opposite directions for providing saidpredetermined time interval of operation in either direction of rotationof said driving means, means including a gearassociated with said'timingmeans operable in a predetermined direction for actu'ating saidswitching means, and means for automatically resetting said timing meansand said switching means after said switching means has been operated.

3. A circuit interrupter normally closed and adapted to be opened aftera predetermined timing interval comprising driving means, meansincluding a driving gear arranged to be connected to said driving meansat the beginning of said timing interval, a traveling pinion meshed withsaid gear, said pinion being provided with a clutch face, a threadedmember upon which said pinion may travel from a iirst position to asecond position upon being rotated by said driving gear, an operatingpinion fixed to said threaded member having a clutch face arranged to beengaged by said clutch face on said traveling pinion, a switching gearmeshed with said operating pinion, switching means including a pair ofcontacts normally closed and arranged to be opened by rotation of saidswitching gear, said timing interval being dependent upon the length oftravel oi.' said traveling vpinion from said first position to saidsecond position, and means including a gear and an energy-storing springfor returning said traveling pinion to said rst position after saiddriving gear has been disconnected from said driving means.

4. A circuit controller adapted to provide a predetermined time intervalof operation by timing means including a traveling pinion having aclutch face, a threaded member upon which said pinion may travel. anoperating pinion secured to said threaded member having `a clutch facearranged to be engaged by said clutch face on said traveling pinion,switching means operated by said operating pinion, and means to manuallyrotate said operating pinion and said threaded member independent of thetraveling pinion for changing said starting position of said travelingpinion, thereby adjusting the timing oi' said controller.

5. In combination with a casing for a circuit controller, saidcontroller having switching means and providing a predetermined 'timeinterval of operation thereof by timing means including a travelingpinion having a clutch face, a threaded member upon which said pinionmay travel, and an operating pinion for said switching means to besecured to said threaded member and having a clutch face arranged to beengaged by said clutch face on said traveling pinion of means forassembling and adjusting the clearance of said clutch faces including ahead on said threaded member accessible from the exterior ot said casingby which said threadedmembermaybeturned.

6. A control device provided with switching means adapted to be operatedafter a predetermined time interval comprising driving means including ashaft mounted for rotation in either direction, a driving gear, anelectromagnetic clutch disposed intermediate said-driving gear and saidshaft arranged to be energizedat the beginning of said time interval forcoupling said gear arid said shaft, means including a pair of travelingpinions meshed with said driving gear adapted to travel from an initialposition in respectively opposite directions and provided with clutchfaces, a pair of threaded members along which said traveling pinions maytravel having secured thereon a-pair of operating'pinionsprovided withclutch faces arranged to be selectively engaged by said clutch faces onsaid traveling pinions in either direction of rotation of said drivinggear, and means including a switching gear meshed with said operatingpinions and adapted to be revolved in a predetermined direction therebyfor operating said switching means, said time interval being dependenton the length of travel of said traveling pinions and being obtainablein either direction of rotation of said driving means.

7. A controlvdevice provided with switching means adapted to be operatedafter a predetermined time interval comprising driving means including ashaft mounted for rotation in either direction; a driving gear, anelectromagnetic clutch disposed intermediate said driving gear and saidshaft arranged to be energized at the beginning of said time intervalfor coupling said gear and said shaft, means including a pair oftraveling pinions meshed with said driving gear adapted to travellfroman initial position in respectively opposite directions and providedwith clutch faces, a pair of threaded members along which said travelingpinions may travel having secured thereon a pair oi' operating pinionsprovided (with clutch faces arranged to be selectively engaged by saidclutch faces on said traveling pinions in either direction of rotationof said driving gear, and means including a switching gear meshed withsaid operating pinions and adapted to be revolved in a predetermineddirection thereby for operating said switching means,

said time interval being dependent on the length of travel of saidtraveling pinions and being obtainable in either direction of rotationof said driving means, and means including a gear and a double actingspring associated with driving 5 gear for returning said travelingpinions to said initial position after said electromagnetic clutch isdeenergized.

8. A time element control device comprising a driving member mounted forrotation in either direction, two rotatable traveling members connectedto .be rotated by said driving member, means mounting said travelingmembers for rotation and for translational movement inoppositedirections when rotated by said driving member, and a control memberoperated by said traveling members in a predetermined directionselectively.

9. A time element control device comprising a driving member mounted forrotation in .either 20 direction, two rotatable traveling membersconnected to be rotated by said driving member in the same directionwith respect to each other, means mounting said traveling members forrotation and for translational movement in opposite directions whenrotated by said driving member, and a control member operated by the oneof said traveling members moving in a predetermined one of saidtranslational directions.

10. A time element control device comprising I a rotatably mountedcontrol member, two driving members operatively connected to saidcontrol member for selective rotation in opposite directions to turnsaid control member in a predetermined direction, a main driving membermounted for rotation in either direction, two rotatable travelingmembers connected to be rotated by said main driving member in the samedirection with respect to each other, and means mounting said travelingmembers for rotation and translational movement in opposite directionswhen rotated by said master driving member to bring one of saidtraveling members into rotary driving relation with one of said drivingmembers and thereby turn said control mem- 4l ber in a predetermineddirection.

ROBERT W. GOFF.

